That has nothing to do with what he said. At the very least, you can leave their modem also set as a router and just put your router behind it (double NAT). Mor

That has nothing to do with what he said. At the very least, you can leave their modem also set as a router and just put your router behind it (double NAT). More likely, you can turn off all of the "router" functions of their modem and still put your own router behind it. There is no way for them to differentiate whether the device behind the modem is a router or a computer.